1. Field of the Invention
This invention relates to a support mechanism of an overflow weir in a sewage DISPOSAL tank.
2. Description of the Related Art
A sewage disposal tank is generally installed on a concrete foundation. Therefore, if the concrete foundation is laid down non-horizontality, the sewage disposal tank inclines quite naturally, and overflow weirs in treatment chambers incline, too, due to this inclination, so that water overflows via only notches on the inclined side and cannot uniformly overflow via all the notches as expected originally with the overflow weir. For this reason, the overflow weir of the sewage disposal tank is ordinarily supported by a support mechanism having a horizontality adjustment function.
A suitable support mechanism of an overflow weir according to the prior art as an comparative example with the present invention is illustrated in FIG. 5 of the accompanying drawings. Namely, both ends of a fitting substrate b are supported at inner upper portions of a treatment chamber a and both ends of a sheet-like overflow weir d equipped with a large number of V-shaped notches c for overflowing water are fixed to the surface of the substrate b by means of set screws e and elongated holes f.
In the support mechanism of the overflow weir according to the prior art described above, both ends of the overflow weir d are fixed by the set screws e. When horizontality adjustment of the overflow weir d is made, therefore, the two set screws e must be loosened individually, the overflow weir d must be supported under the horizontal posture using the two set screws e as the guide while the screws are kept loosened and moreover, these two set screws e must be finally fastened under this support state. However, these procedures are carried out while the overflow weir d is allowed to freely move in irregular directions such as in longitudinal and oblique directions, and it is very difficult for this reason to correctly set the overflow weir to the horizontal posture without permitting it to freely move.